I have used that MFS sled with 2x's for rails.
Hey Luke, it is great to see you back. That looonnnggg weekend was causing me to have serious withdrawal symptoms.
While you were away (BTW: congrats to the grads), my GS and i were running some maple boards thru my DW 734 planer when the planer broke down. It was the main drive belt, but there were no signs of wear except where it had melted in one spot. If there had been a wear pattern, i would not have worried, even tho it is only around 20 years old [unsure]. But the wear was only the melted spot where it separated. My thoughts were: "Why did it burn in only one spot?" It was Saturday afternoon, so I could not get a new belt anyhow. (I have not had time to investigate further as the week before Memorial Day is my second busiest week for lawn work of every year and I am my full crew. [unsure]) I decided I Would plane the boards by hand.
There are 4 of them 8-1/2" by 80", so how hard could that be? I had a couple of spare pieces so i decided to practice. After a couple of hours, including resharpening my plane iron, I decided to go a different route. I will take the boards to the supplier where i gt them and have them plane both sides. They had offered to plane the lumber down when i bought the pile last fall. They would have done 4square for me then for probably less than they will do it now. But i am sort of working against a deadline for the finished table. (I will try to show pics when it is all done)
The end result of my efforts has been an increased respect for your efforts to level your Roubo bench.
Tinker